Carex tetrastachya

Plants densely to loosely cespitose; rhizomes black, short to ± elongate in old clumps. Culms 30-100 cm; vegetative culms few, inconspicuous, usually fewer than 12 leaves, not strikingly 3-ranked. Leaves: sheath summits with adaxial hyaline band, truncate to rounded, sometimes prolonged beyond collar; distal ligules to 5 mm; blades 3-5 per fertile culm, 13-40 cm × 2.5-5 mm. Inflorescences densely to usually open, at least proximally, silvery white, 2.5-6 cm × 10-25 mm; proximal internode (4-)8-11 mm; 2d internode 4-8 mm; proximal bracts bristlelike to 5 cm. Spikes 2-4(-5), distant, distinct, ovoid to globose-ovoid, 11-18 × 8-13 mm, base attenuate on terminal spike, rounded on lateral spikes, apex rounded. Pistillate scales white-hyaline with light brown 1-3-veined midstripe, lanceolate to ovate, 4-6 mm, as long as and narrower than perignyia. apex acuminate with subulate tip or awnlike, awn of at least proximate staminate scales and sometimes proximal pistillate scales 0.1-0.9(-2.4) mm, scabrous. Perigynia 15-80 in larger spikes, ascending, white with light green margins, veinless over achene on each face, orbiculate or little wider than long, flat, 5.5-8(-8.7) × 3.5-6.3 mm, 0.4-0.5 mm thick, margin flat, including wing 1-2 mm wide, smooth; beak pale brown to reddish at tip, flat, (1.4-)1.6-2.5(-3.4) mm, ciliate-serrulate, abaxial suture inconspicuous or brown, distance from beak tip to achene 2.5-4 mm. Achenes oblong-elliptic, 2.5-3 × 1.5-2 mm, 0.4-0.5 mm thick. n = 30+III. 2n = 64, 66.

Fruiting spring. Mesic to moist prairies, roadside ditches, shores; 0-300 m; La., Okla., Tex.